Hey there everyone... I've been a lurker around here for a long time, but never had the need to post... until now.

To catch everyone up, I've been a Decware Plans owner for about 3-4 years... built the 10 and 12" deathboxes... both still in operation around here. All the Imperial stories have been getting me interested in starting a build.

Admittedly, I've found that Steve makes himself scarse, to post, and it has led to some really stupid suggestions by the end users... IE, trying to cram an Imperial in a car is just stupid, because of the giant wave it makes... standing waves and cancelation would really make a suck-fest. But again, it's fun to suggest things we wouldn't do ourselves and let others be our guinea pigs.

That said...... My name is Bill and I like to build loudspeakers. Like Steve, and others, I'm a musician as well as a comptuer specialist....I have dozens of hobbies... lets just say I'm patient and always curious.

Many of you know of the PA speaker designer Bill Fitzmaurice.... He designed the Tuba Sub series, the DR horns... you get the idea... Anyway, I made a deal similar to what some of us have here with Steve... get the plans for all the speakers for one money.... cool right? I built both the Wedgehorn 10 and the original Wedgehorn... hardly hi-fi, but a very hearable stage monitor... I intend to try the DR horns and the Tuba Subs next....

While having discussions in his forum, I asked about vintage speaker designs... like the Altec VOT, and the Jensen Imperial... Needless to say it's a growing topic. I'm not trying to start a war, but what I read here, and what I read there are total opposites. I'd really like to hear from people who have built the full range imperial.... I want to make Theatre/Auditiorium speakers in the near future...

It's really something to hear all the buzz here... and then hear that the Imperial is a dead horse not worth beating......

Please no wars... I'd like to hear from Steve and other designers. Bill Fitzmaurice has some good designs, but he's been quick to shut down other designs.... on the old forum I remember bringing up death box... I was told "It's better than a normal sealed box, but not even in the same class as Tuba"...... My DB10 (Dayton Quattro loaded) is a very welcome addition to my home stereo... sounds great, and very musical... plus it's an easy build compared to Tuba... I say DB gets props for performance/difficulty if nothing else.

Anyway.... I want to know who's heard the Imperial.... and the Tuba... and the VOT... are the vintage designs really dead animals? Something tells me that Bill F is too quick to dismiss the designs, but there may be some truth in there....

[quote author=VexorgTR link=1148275933/0#0 date=1148272333]Admittedly, I've found that Steve makes himself scarse, to post, and it has led to some really stupid suggestions by the end users... IE, trying to cram an Imperial in a car is just stupid, because of the giant wave it makes... standing waves and cancelation would really make a suck-fest. But again, it's fun to suggest things we wouldn't do ourselves and let others be our guinea pigs. [/quote]I'd just like to state, I take offense to this part of the post.

I am a sound junkie and computer engineer as well, also do some civil engineering and custom box building on the side. I know what I'm doing. Whether or not an Imperial-type horn enclosure would work in a van is pure theory, at this point in time, just like the Imperial itself was at one point; just like all enclosure designs were at one point.

I've dabbled in the Imperial quite a bit, but for reason of not a large listening room (or van yet), I haven't built one. Give me a room, and I build your Imperial and Tuba Sub so you can have a side by side comparison. Or rather than attacking the inventive and/or attempting to start a war between the two sites, you could build one yourself and do the side by side. I'm sure if it doesn't perform to your liking, someone here can help you fix it(if done wrong) or would be happy to take it off your hands.

geez, what's wrong in trying the imperial in a car ?it's not like you would go around saying: listen to how bad steve's design sounds in a car. if i'd have an imperial and an van, i'd try it. if it works, good 4 me. if not, at least i haven't lost anything. maybe i prevented other bass junkies like myself and jet from doing it again

[quote author=Lee in Arkansas link=1148275933/0#2 date=1148297412]I'd just like to state, I take offense to this part of the post.

I am a sound junkie and computer engineer as well, also do some civil engineering and custom box building on the side. I know what I'm doing. Whether or not an Imperial-type horn enclosure would work in a van is pure theory, at this point in time, just like the Imperial itself was at one point; just like all enclosure designs were at one point.

I've dabbled in the Imperial quite a bit, but for reason of not a large listening room (or van yet), I haven't built one. Give me a room, and I build your Imperial and Tuba Sub so you can have a side by side comparison. Or rather than attacking the inventive and/or attempting to start a war between the two sites, you could build one yourself and do the side by side. I'm sure if it doesn't perform to your liking, someone here can help you fix it(if done wrong) or would be happy to take it off your hands. [/quote]

Hey Jet I take offense two. or is it too or to or 2

Jet - I did not know you wuz edumacated??? creative and smart and married off :).

Before you all start riding me like a pony at a kid's birthday... perhaps you should read the designers notes... and I quote.

"APPLICATIONS

Before you build one or a pair of these speakers you really should know the intended application of which there are three.

Subwoofer - this is the simplest implimentation of the cabinet. All you have to do accomplish decent response across 2 octaves between 25Hz and 100Hz. You can also use a very wide variety of drivers for this application. P.A. Speakers/theater - As shown above. High Fidelity Playback - As shown above with special considerations or with a single 15 inch coax, using the 2nd woofer for 50 Hz and below. In all applications there is one consistancy - the room must be large. 24 x 24 feet is really about the minimum and frankly rooms 2 to 4 times this size would be less problematic.

SPL competitions are won with <= 50hz tones; in sedans, stationwagons, pickups, vans, etc. Why would the type of box render the application obsolete when it produces frequencies in the target range?

[quote author=Gexter link=1148275933/0#4 date=1148300645]

Hey Jet I take offense two. or is it too or to or 2

Jet - I did not know you wuz edumacated??? creative and smart and married off :). [/quote]Freaky, huh? I surprise myself sometimes.

BTW, it's "too."

[quote author=Lee in Arkansas link=1148275933/0#2 date=1148297412]Whether or not an Imperial-type horn enclosure would work in a van is pure theory, at this point in time, just like the Imperial itself was at one point; just like all enclosure designs and applications were at one point. [/quote]I'd also like to add what is italicized in the above quote of myself.

Let me start by saying that I do not have the plans for the Tubas. Let me tell you why.

Look at the Tuba 36 page. The frequency response chart shows response drops like a stone at 40 hz. There is some mention of some vertical baffle with extension to 15 hz - if it's true, why isn't it shown? Or is it maybe -10db or even more at 15 hz? The graph doesn't look like anything special.

Look at the 3d pics below the graph. This thing looks exactly like the imperial with a different folding and loading scheme. You can load the imperial any way you want and fold it differently too. The horn flare looks to me to be very similar to the imperial and the physical size of the box is almost identical.

You show me a horn that fits in a box the size of the imperial or the tuba 36 that gets extension flat from 15 hz to 100 hz and I'll give $1000 for the plans.

[quote author=bassboy link=1148275933/0#7 date=1148306020]You show me a horn that fits in a box the size of the imperial or the tuba 36 that gets extension flat from 15 hz to 100 hz and I'll give $1000 for the plans. [/quote]Linkwitz Transform a sealed box feeding an expontial front horn?

Just to be fair, Bill's Tuba does not seem like a bad design. The compression chamber is smaller, meaning the horn flare is probably a bit longer because they are the same size.

But based on the frequency response graph, there really doesn't seem to be much difference in output at all.

But again, to be fair, the Jensen plans are free and Bill's aren't. I wouldn't advise trying to follow the Jensen plans to the letter, but they give enough info to guarantee success if you know what you are doing. If you don't, you need to buy Steve's plans.

Also, the imperial has more options for driver loading. You can easily make it front loaded, back loaded or the completely different Imperial SO. Also, the back loaded alignment allows for a full range design. You just don't have any ability to make these changes with Bill's Tuba.

The thing is, if you are in the market for a 40 hz bass cornerhorn, you can't go wrong with either design. But if you want flexibility, it is built right into the Imperial.

this last winter i built a table tuba as i was told by Bill that it is what i was looking for.It plays low and i mean low!! so low i cant hear it.....now i was told i built it wrong by using 3/4 mdf instead of 5/8 mdf and that i did a poor job of bracing ect .posting my opinion on the box and all i got was alot of Bills fans telling me i was a moron.there were a couple of guys there that were good and helped me alot.I did try other drivers and that made a difference but in the end Bills tuba just has no place in a home theatre or a system that needs to play loud with punch.I am still building and learning and love the plans on this site .as far as a Imperial in a van.... my years in auto sound building cars for guys with thick wallets is this.solid wall with lots of 10's so you get no space in between them and then a wack of power with lots of gell cells and many farads of caps.shayne

I remember someone was dissing the Decware Deathbox and saying Auto Tuba could kick its ass... considering that the AutoTuba is twice as big, and infinately harder to build... it's a lame comparison.

I mainly wanted to build the "Wedgehorns" that are on there.. as a pro musician I can use them.. WHen I finished each one.. the original and the 10... they totally sounded like crap.. no joke.. after breaking in the driver, they became quite good. I wrote this up on the forum and was told I was crazy by Bill's Yes Men... Bill said that it was about half of the cone's break in and half of me "getting used to the speaker".... If you have to "get used to it" it's not a great sounding thing.

The Wedgehorns are good stage monitors... no hi-fi, but very audible on stage.. more than the usual JBL's Communities, and Yamahas I've used before.

I plan to try a DR250 Horn next... Those designs are not for the beginner... sheesh.

Don't take this too far. As far as I know Bill is a very reputable designer and his products are very valid in the context for which they were designed, which, for the most part is pro audio. Pro audio is usually very very loud and usually does not extend very low. The imperial can be used for pro audio but has many other incarnations as well.

I am confused as to what this thread is meant to be. Granted you did say you didn't want to start a flame war, yet the first post seems to request it at the same time.

In any case, BassBoy is right, Bill F's designs are good for their intended uses. Which entail P.A. Audio. They need to be loud and sound clear in the musical range. Hence the dropoff after 40hz on almost every design.

The Jensen is on the other hand a completely different animal in every aspect aside from the Horn somewhere in each design. It is made to take 2 large woofers low and clean. Loudness is a very nice side-effect.

The DeathBoxes on the other hand are simply regular ported boxes with a twist: a tunable insert to greatly increase the number of drivers that will work in them, and decrease the knowledge necessary to make them sound good. Simply slide an insert till you are happy. Not to mention the size is smaller yet yeilds flat extension below 40hz.

I will stand behind Jensen designs and Steves adjustments.I have thought of the bass tuba but can fullfill all my Bass requirements with Decware product and then some. I don't think I would ever pay for another sub design beyond the decwares.Any other designs that I have been interested in are free and all you need is a pencil and a calculater and some time.

Each has its application. and that can really depend on what a person likes. I really dislike the sound of a DB 10 for HTI really like the DB12 for HT. But I know I may ( may) do better with another design.For the ultimate HT for me it would be a Full size Decware Imperial with a transflex as an experimental project. I think with some work it would be awsome if it was not already.But I will not know until I build one for sure.

Lets keep it going so we can get a real comparison from those who had built both.. thanks shayne for your input

#2.... So far the Bill F speakers I've built have done better than the off the shelf units...

#3... Bill F Says the Jensen is not worth persuing... and it's just plain old news....

#4.... There must be something to the imperial, but the only person who really raved about the full range is Steve... the SO version is getting a nice buzz, but again, I'm thinking Theatre speaker.... Full range, major dispersion....

I am digging for some serious thoughts from some serious listeners.......... and I'm trying to avoid illogical ideas and concepts.

I know that many a time I come off as a bit cold and blunt...Then again, I'm sort of annoyed that the Jensen Imperial is being sold here as a one size fits all... and it's too friggn big for a bedroom, way to friggn big for a car.... you get the idea. If I build a pair, I want them to sound big, and clear... I plan to donate them to a very sizeable church.

Every now and then I check in to see what's going on and saw this thread on wide range Imperials. I've built more than one set of these speakers over the years, the latest set with additional bracing similar to Steve's SO design that was not in the original plans. Coming from both an EE and orchestral concertmaster background, I would underline Steve's caution about determining your application as absolutely critical. I wouldn't build the SO because I have no interest in music that goes below 30Hz, the 5db down point with the original lab design at left. For those who do, and want a boost in SPL at the lower end, more power to you! That kind of boost just doesn't sound like what I hear sitting on the stage in a large orchestra and being a part of recreating a classical piece of music. Like every one of you, I've listened to a lot of speaker designs, and can only say that for orchestral and pipe organ program material, the original design using the G-610 is still hard to beat. You won't get the bass you feel with the SO's, but you won't hear that in the concert hall, either.

Unfortunately, there are so many variables that it is almost essential to hear a pair in your listening environment and with your kind of music. Those variables can range all the way from the equivalent of a dummy load in antenna terms (Imperial in a van) to an infinite impedance load (an open field) and all the classic transmission line matching equations and techniques (in sonic equivalents) apply here.

Interesting observation Mike, and I suppose its true from your stand point. I listen to a lot of different music, and classical is not big these days, I have a lot vinyl classical music, but CD's dont seem to have the dynamic range to do the music justice. I do like a good sub for other genr'es of music though. But I get what you were saying, get what fits.

Get what fits is the best advice.sometime you really have to take a look at the room, the music, and what you wanna hear in it.Then make a leap by what people with the same tastes in music say about it. Can't say any one speaker will last to your dying day for most. tastes changesSometimes even a speaker that you look at and say " boy I like those" after all the other needs are met.

Then again, I'm sort of annoyed that the Jensen Imperial is being sold here as a one size fits all... and it's too friggn big for a bedroom, way to friggn big for a car.... you get the idea.

I feel like you're taking one small idea, and basing your entire assumption about the imperial thread off of one idea. When was it ever wrong to throw around an idea? Many of the threads in this forum are specific to ideas but there are always some that are a little out there, and i tip my hat off to those who like to defy logic or think up what some would concider ludacris ideas. VexorgTR I'm annoyed, that you come in to a forum, and "get annoyed" at one thread and sort of put the entire forum down because of that. Yes, the imperial in a car doesn't sound like a good idea, but have you tried it? Many a times things happen when they shouldn't and who knows, it could sound great. The last time i checked, there were 150 subjects posted in the Imperial forum, and you shun the forum for 1 subject? You you came here looking for ideas and say Quote:

I am digging for some serious thoughts from some serious listeners.......... and I'm trying to avoid illogical ideas and concepts.

, i believe you are disrespecting many members here, myself included, who may say an "illogical idea" but that is because my lack of knowledge of speakers.(i had my imperial in my bedroom for about 2 months before i moved it to the basement, it sounded great to me) Many like to push the envelope. So please, respect the members of this forum and their Quote:

just one other thing i have learned.take 1 box and lode it with a 15 and a horn then listen to it .then take what you just listened to and go to a school then a bus stop and so on.it will in most cases always sound different just like any design from here or any other site.for a test i built a 4 ft cube box and made plates for different drivers and also ports that i could cover and open.then i used a small powered sub amp and x over that you would find in a store bought powered sub.now i did this so i could better understand speaker specs and WOW they are alot of thing i found out.my first test was with an 8 inch driver i had from mcm in the box with no port i could drive it to where it would pop but there was no audible sound of bass.so i uncovered a port and instantly BOOM BOOM BOOM .I did this with 9 other drivers and all were differnt.so my point??? you may have a killer box and a killer driver but maybe not a killer match.

Can someone clarify this for me? (Quoted directly from Bill Fitzmaurice)Quote:

If you put two 8-ohm drivers parallel wired in one double-wide box the impedance must remain 6 ohms. Since the electrical impedance is 4 ohms the air column is only adding 2 ohms to the load. That makes perfect sense, as using two drivers instead of one does not result in 3dB higher sensitivity.

Since the sensitivity with two drivers is the same as with one that means that the resisitive load of the box is halved. If it remained the same then the second driver should cause a 3dB sensitivity increase, and it does not. Think of the second driver as a sponge that soaks up half of the acoustic impedance.

Maybe I'm just uneducated, but I thought doubling the drivers gave you a 3db increase, all other factors the same?

Adding a second speaker yields a 3db increase. Adding twice as much power yields a 3db increase. Adding a second speaker, and adding power to it(doubling the power of the channel) yields a 6db increase.

He saying inside the same box, that the air becomes much more resisitive since 2 drivers are pulling on it.

Heres a better way to think about it.

In your 1 cu ft box, you have 1 10 inch subwoofer. The subwoofer has an acoustical impedance of 8 ohms, and the air in this configuration adds 1 ohm of resistance. (Due to the change in volume when the cone moves back and forth.)Total impedance of 8-9 ohms.

If you add a second sub exactly the same make, the acoustical impedance halves. It is now 4 ohms. The air inside the box will be pulled twice as hard, so the force on each driver, will be twice that of one driver, so 2 ohms. Not to mention that 2 drivers experience it. So a total of 4 ohms from the air is added.Total impedance is again around 8 ohms.

So where does this 3 db increase come from? Well in this case there would be no increase. The same amount of power in no matter what. So there can be no increase.

The 3db one would expect when adding another woofer is usually only when impedance is halved. Hence a second identical subwoofer in its own enclosure wired in parrallel. Half the impedance. Twice the power goes to the sub, however the same amount as originally to each single sub. 3 db.

doubling the drivers in the same box does not give you a 3 DB increase.

Or so I thought!Not hard to check, I just am too lazy to wander away from this site or dig in the forums.

I would read the whole thing instead of part of it. sometimes something is not written well and confusing. I have heard the craziest stuff but thats not what was intended.I write stuff I look back and say What was I thinking?

The quote makes more sense if you understand the way a front-loaded horn works(as opposed to an Imperial). All sound from Bill F's designs comes from the horn; there is no direct radiation from the cone. Front-loaded horns have a much stronger influence than the T/S parameters of the driver. I have probably oversimplified this and I'm sure Bassboy and others will be helpful in expanding the concept.

As far as electrical impedance, if two drivers are splitting the power, do you really get 3dB increase? This is one of the most debated ideas I have seen over many forums. Doubling the cone area then splitting the same amount of power(one variable at a time), do you get an increase? Or do you have to give each speaker the amount that the single drive got?

This is the way I understand it. If you wire two identical 8 ohm speakers in parallel (let's say in 2 separate boxes to avoid that issue) then you end up with a 4 ohm load. Your amp can generally deliver twice the power into 4 ohms compared to 8 so you end up with two speakers each getting the same amount of power as your original single 8 ohm speaker.

All else being equal, those 2 speakers together will give you a 3 db increase because each is playing just as loud as the original single speaker, but you are putting in twice the power. There's no free lunch.

Now that the SO is part of the regular Decware lineup and plans are available, the SO has become a viable alternative to the average subwoofer. For my needs the regular imperial just does not go low enough.

I was really hoping for some white papers with real world numbers, like the deathbox, but it doesn't look like it's going to happen that way. Anyway, Steve's assertion is that there is no attenuation from 80 hz down to 20, and I believe him but his setup is much different than most people would have. His is measured with 2 SO's, mouth to mouth, sitting on a huge bass trap, and as far as I know we still have no figure whatsoever with regards to sensitivity. If I am wrong about Steve's setup or measurements, I apologize.

Regardless, this thing is going to play low enough that it should leave nothing at all to be desired with music playback.

Home theatre is a different story, and it would seem that the SO is sitting on the borderline to being adequately low enough for HT as well, depending on personal taste.

I'm not sure when the plans were posted, but they've been there at least a few hours now. Most people don't have the plans, myself included, but in the spirit of "illogical ideas and concepts" it may be time to start modding the best Decware product to date.

It would seem to me that changing the horn flare could substantially lower the tuning. By making the flare a bit longer, and the expansion rate a bit less aggressive, the horn flare tuning could probably safely be lowered at least a few hz, the drawback being a bit of ripple in the upper part of it's frequency response.

Since the SO is already playing much lower than the horn tuning would suggest I am not sure exactly what effect this mod would have, and without plans I'm not sure if Steve hasn't already changed the horn flare a bit.

The point is this. I wouldn't be me if I wasn't throwing around "illogical" and probably downright stupid ideas, but if there is any chance at all that a horn this size could extend FLAT down to 15 hz....

well that would be like a Christmas miracle and I can already imagine the made for tv after school specials, lol.

They were added very recently. I'm not sure exactly when, as I have not been checking because I have no intention to make one anytime soon. They won't fit into my room unless I rip a big hole in the wall.

Various people have been begging, pleading, whining and generally waiting for these plans for a LONG time now.

Regarding a sine sweep at last Decfest, Steve has stated that there is no attenuation from 80 - 20 in his listening environment. That's the closest thing to a published fact that I have seen yet. That alone makes it the lowest tuned horn of it's size I have ever seen. If it can do this with anywhere near the sensitivity of the original version, it is very probably the best cornerhorn design IN THE WORLD to date. (The 15 hz part is just speculation based on horn theory and possible mods to the design, Steve has never insinuated that the SO is capable of 15 hz flat.)

I'm just wondering what it could be capable of with a few minor changes but the overall same size.

Randy probably does not have the necessary equipment to perform these tests. I have a feeling his taste for music is based more on emotion and perception than hard numbers anyway. Not to mention that results will vary wildly in different environments.

Randy is not the only one that has been living with SO's, but strangely enough, no one with the necessary experience seems very willing to discuss the merits of the first breakthrough in horn technology in 50 years.

[quote author=bassboy link=1148275933/30#39 date=1148580354] but strangely enough, no one with the necessary experience seems very willing to discuss the merits of the first breakthrough in horn technology in 50 years. [/quote]

Kinda like everytime someone invents an engine that runs on water, they mysteriously die. ???

[quote author=bassboy link=1148275933/30#39 date=1148580354]Randy probably does not have the necessary equipment to perform these tests. I have a feeling his taste for music is based more on emotion and perception than hard numbers anyway. Not to mention that results will vary wildly in different environments.

[/quote]

It's true ..... every word ..... ???

I don't even have an SPL meter .....

If it sounds like music and floats my boat, I'm a happy camper .....

However, if someone would like to make a trip to Caintuck and bring the needed equipment, they are welcome.